Everyday Stoichiometry

When you make food by following a recipe, you are essentially combining stoichiometric ratios of ingredients together. For example, a recipe for a dozen chocolate chip cookies calls for 1 stick of butter, 1 cup of sugar, 1 egg, 1 ⅛ cups of flour, and 1 cup of chocolate chips. In order to make the exact type of cookie that the recipe is describing, you will have to use the exact ratio of ingredients as described in the recipe. However, let’s suppose you want to be a cutting edge, daredevil chef and use the exact recipe described, except use 5 cups of flour and no eggs. Well, your end result would still be edible to some degree, but for the most part it probably will look pathetically unappetizing. The end result you produce with this stoichiometric relationship of ingredients differs from the relationship that is called for by the recipe, thus yielding a product that is not the same as what is called for by the recipe.

Creative Applications

1. What if you used 2 cups of sugar, 2 eggs, 2 ¼ cups of flour, and 2 cups of chocolate chips? Would the end product still be chocolate chip cookies?

2. In the reaction ofSnO2+ 2 H2→ Sn + 2 H2O, what is the stoichiometric relationship between H2and SnO2?